System and method for producing un-hydrogenated and hydrogenated c9+ compounds

ABSTRACT

A system and method for processing pyrolysis gasoline is disclosed. The system and method involves separating a pyrolysis gasoline stream to produce a first stream comprising primarily un-hydrogenated C 9+  compounds. The separating of the pyrolysis e gasoline occurs without hydrogenation being carried out on the pyrolysis gasoline before the separating.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. ProvisionalPatent Application No. 62/874,401, filed Jul. 15, 2019, the entirecontents of which are hereby incorporated by reference in theirentirety.

FIELD OF INVENTION

The present invention generally relates to the processing of pyrolysisgasoline (pygas). More specifically, the present invention relates to aprocess of processing pyrolysis gasoline to produce un-hydrogenated C₉₊hydrocarbons and hydrogenated C₉₊ hydrocarbons.

BACKGROUND OF THE INVENTION

A common process in the refining of hydrocarbon feedstocks, such asnaphtha, is steam cracking. In the steam cracking (pyrolysis) process,the hydrocarbon feedstock is superheated in a reactor to temperatures ashigh as 750-950° C. For the cracking process, a dilution steam generatorsupplies dilution steam to the reactor to reduce the partial pressure ofthe hydrocarbons. The superheated hydrocarbons are then rapidly cooled(quenched) to stop the reactions after a certain point to optimizecracking product yield. Pyrolysis gasoline is one of the products of thecracking process and may include components such as aromatics, olefins,and/or diolefins, among others. Typically, the pygas is hydrogenatedbefore further processing to produce finished products such as benzene,toluene, and xylene (BTX).

Gasoline hydrogenation units (GHU) are commonly used in the chemicalindustry to saturate unstable compounds such as diolefins and styrene.Olefins and sulfur compound are also hydrogenated to meet final productspecifications. After hydrogenation, different product cuts areseparated based on downstream demand. For example, after hydrogenationof pyrolysis gasoline, a C₉₊ cut is normally separated at a deoctanizerto produce hydrogenated wash oil and hydrogenated C₉₊ residue.

WO 2018/002810 A1 relates to a separation system for separating a feedstream comprising C6+ hydrocarbons, the system comprising: i) a firstdistillation column for producing a first light stream comprising C6−hydrocarbons and a first heavy stream comprising C7+ hydrocarbons,wherein the first distillation column is operated between a lowestpressure and a highest pressure, ii) a second distillation column forproducing a second light stream comprising C6− hydrocarbons and a secondheavy stream comprising C7+ hydrocarbons, wherein the seconddistillation column is operated between a lowest pressure and a highestpressure, wherein the lowest pressure of the second distillation columnis higher than the highest pressure of the highest distillation columnand iii) a heat exchanger comprising a first reboiler for reboiling apart of the first heavy stream to produce a first boiled heavy streamand a second condenser for condensing the second light stream to producea second condensed light stream, wherein the first reboiler and thesecond condenser are arranged such that heat released from the secondcondenser is used as heat for the first reboiler.

BRIEF SUMMARY OF THE INVENTION

As described above, conventional processes for processing of pyrolysisgasoline produce hydrogenated C₉₊ hydrocarbons. However, there is also ademand for un-hydrogenated C₉₊ hydrocarbons. As far as is known,presently, there is no process that produces both un-hydrogenated andhydrogenated products concurrently. A solution to address thisdeficiency of conventional processes has been discovered. The disclosedprocess is premised on separating un-hydrogenated C₉₊ hydrocarbons frompyrolysis gasoline upstream of a GHU so that un-hydrogenated C₉₊hydrocarbons can be recovered as a product and/or hydrogenated C₉₊hydrocarbons can be recovered as a product. The discovered processprovides the flexibility of producing (1) only un-hydrogenated C₉₊hydrocarbons (separation upstream of GHU and not further hydrogenated),(2) un-hydrogenated C₉₊ hydrocarbons and hydrogenated C₉₊ hydrocarbons(separation upstream of GHU and GHU operated to process only a portionof the un-hydrogenated C₉₊ hydrocarbons), or (3) only hydrogenated C₉₊hydrocarbons (GHU operated to process all of the un-hydrogenated C₉₊hydrocarbons).

Embodiments of the invention include a method of processing pyrolysisgasoline, where the method involves separating a pyrolysis gasolinestream to produce a first stream comprising primarily un-hydrogenatedC₉₊ compounds. According to embodiments of the invention, the separatingof the pyrolysis gasoline is carried out upstream of the hydrogenationunit.

Embodiments of the invention include a method of processing pyrolysisgasoline to concurrently produce a first stream comprising primarilyun-hydrogenated C₉₊ compounds and a second stream comprisinghydrogenated C₉₊ hydrogenated compounds. The method includes separatinga pyrolysis gasoline stream to produce the first stream comprisingprimarily un-hydrogenated C₉₊ compounds and further includeshydrogenating a portion of the first stream to produce the second streamcomprising hydrogenated C₉₊ hydrogenated compounds.

The following includes definitions of various terms and phrases usedthroughout this specification.

The terms “about” or “approximately” are defined as being close to asunderstood by one of ordinary skill in the art. In one non-limitingembodiment the terms are defined to be within 10%, preferably, within5%, more preferably, within 1%, and most preferably, within 0.5%.

The terms “wt. %”, “vol. %” or “mol. %” refer to a weight, volume, ormolar percentage of a component, respectively, based on the totalweight, the total volume, or the total moles of material that includesthe component. In a non-limiting example, 10 moles of component in 100moles of the material is 10 mol. % of component.

The term “substantially” and its variations are defined to includeranges within 10%, within 5%, within 1%, or within 0.5%.

The terms “inhibiting” or “reducing” or “preventing” or “avoiding” orany variation of these terms, when used in the claims and/or thespecification, include any measurable decrease or complete inhibition toachieve a desired result.

The term “effective,” as that term is used in the specification and/orclaims, means adequate to accomplish a desired, expected, or intendedresult.

The use of the words “a” or “an” when used in conjunction with the term“comprising,” “including,” “containing,” or “having” in the claims orthe specification may mean “one,” but it is also consistent with themeaning of “one or more,” “at least one,” and “one or more than one.”

The words “comprising” (and any form of comprising, such as “comprise”and “comprises”), “having” (and any form of having, such as “have” and“has”), “including” (and any form of including, such as “includes” and“include”) or “containing” (and any form of containing, such as“contains” and “contain”) are inclusive or open-ended and do not excludeadditional, unrecited elements or method steps.

The process of the present invention can “comprise,” “consistessentially of,” or “consist of” particular ingredients, components,compositions, etc., disclosed throughout the specification.

The term “primarily,” as that term is used in the specification and/orclaims, means greater than any of 50 wt. %, 50 mol. %, and 50 vol. %.For example, “primarily” may include 50.1 wt. % to 100 wt. % and allvalues and ranges there between, 50.1 mol. % to 100 mol. % and allvalues and ranges there between, or 50.1 vol. % to 100 vol. % and allvalues and ranges there between.

Other objects, features and advantages of the present invention willbecome apparent from the following figures, detailed description, andexamples. It should be understood, however, that the figures, detaileddescription, and examples, while indicating specific embodiments of theinvention, are given by way of illustration only and are not meant to belimiting. Additionally, it is contemplated that changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description. Infurther embodiments, features from specific embodiments may be combinedwith features from other embodiments. For example, features from oneembodiment may be combined with features from any of the otherembodiments. In further embodiments, additional features may be added tothe specific embodiments described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding, reference is now made to thefollowing descriptions taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 shows a system for processing pyrolysis gasoline to produce astream comprising primarily un-hydrogenated C₉₊ compounds, according toembodiments of the invention;

FIG. 2 shows a process for processing pyrolysis gasoline to produce astream comprising primarily un-hydrogenated C₉₊ compounds, according toembodiments of the invention;

FIG. 3 shows a system for processing pyrolysis gasoline to produce astream comprising primarily un-hydrogenated C₉₊ and hydrogenated washoil compounds, according to embodiments of the invention; and

FIG. 4 shows a process for processing pyrolysis gasoline to produce astream comprising primarily un-hydrogenated C₉₊ and hydrogenated washoil compounds, according to embodiments of the invention.

FIG. 5 shows a system and process for processing pyrolysis gasoline toproduce un-hydrogenated C₉₊ and un-hydrogenated wash oil compounds,according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Gasoline hydrogenation units (GHU) are commonly used to saturateunstable compounds such as diolefins and styrene found in pyrolysisgasoline. Olefins and sulfur compounds are also hydrogenated to meetfinal product specifications. After hydrogenation, different productcuts are separated based on downstream demand. For example, afterhydrogenation of pyrolysis gasoline, a C₉₊ cut is normally separated atthe deoctanizer to produce hydrogenated wash oil and hydrogenated C₉₊residue. This process, however, does not contribute to meeting thedemand for un-hydrogenated C₉₊ products. A solution to address thisdeficiency of the conventional process has been discovered. Thediscovered process is premised on separating un-hydrogenated C₉₊hydrocarbons from pyrolysis gasoline upstream of a GHU so thatun-hydrogenated C₉₊ hydrocarbons can be recovered as a product and ashydrogenated C₉₊ hydrocarbons can likewise be recovered as a product.

FIG. 1 shows system 10 for processing pyrolysis gasoline to produce astream comprising primarily un-hydrogenated C₉₊ compounds (e.g.,un-hydrogenated hydrocarbons), according to embodiments of theinvention. FIG. 2 shows process 20 for processing pyrolysis gasoline toproduce a stream comprising primarily un-hydrogenated C₉₊ compounds,according to embodiments of the invention. System 10 may be used toimplement process 20.

According to embodiments of the invention, process 20 includes, at block200, separating pyrolysis gasoline stream 100, in separation unit 121 toproduce stream 101 (C₉+ compounds/stream), which comprises primarilyun-hydrogenated C₉₊ compounds. Wash oil is used to control the build-upof polymers on cracked gas compressors, turbines, seals, and heatexchangers. A good wash oil has a fairly high initial boiling point sothat it won't immediately flash to vapor, combined with a high C₉₊aromatic content for dissolving polymeric compounds. The wash oildescribed herein is hydrogenated to saturate the dienes before using tocontrol the build-up of polymers. Stream 101 may include 10 to 100 wt. %C₉₊ compounds and all ranges and values there between, including rangesof 10 to 20 wt. %, 20 to 30 wt. %, 30 to 40 wt. %, 40 to 50 wt. %, 50 to60 wt. %, 60 to 70 wt. %, 70 to 80 wt. %, 80 to 90 wt. %, and 90 to 100wt. %, and 0 to 90 wt. % wash oil and all ranges and values therebetween, including ranges of 0 to 10%, 10 to 20%, 20 to 30%, 30 to 40%,40 to 50%, 50 to 60%, 60 to 70%, 70 to 80%, 80 to 90%, and 90 to 100%.

According to embodiments of the invention, block 201 includes flowing atleast a portion of stream 101 to GHU reactor 115 and hydrogenating thatportion or all of stream 101 in GHU reactor 115 to produce stream 102comprising hydrogenated C₉₊ compounds (e.g., hydrogenated hydrocarbons).In other words, in embodiments of the invention, all of stream 101 maybe hydrogenated or, as shown in FIG. 1, stream 101 may be separated intostream 101-1 and stream 101-2 and only stream 101-1 is hydrogenated inGHU reactor 115. In some embodiments, GHU reactor 115 is not operatedand, instead, is bypassed such that stream 101 is flowed to flash drum116 so that only un-hydrogenated C₉₊ compounds are produced. In thisway, system 10 is adapted to have the flexibility to produce (1) onlyun-hydrogenated C₉₊ compounds (GHU reactor 115 not operated), (2)un-hydrogenated C₉₊ compounds and hydrogenated C₉₊ compounds (GHUreactor 115 operated to process only a portion of the un-hydrogenatedC₉₊ compounds), or (3) only hydrogenated C₉₊ compounds (GHU reactor 115operated to process all of the un-hydrogenated C₉₊compounds). Accordingto embodiments of the invention, the reaction conditions in GHU reactor115 include a temperature in a range of 100 to 200° C. and all rangesand values there between including ranges of 100 to 110° C., 110 to 120°C., 120 to 130° C., 130 to 140° C., 140 to 150° C., 150 to 160° C., 160to 170° C., 170 to 180° C., 180 to 190° C., and 190 to 200° C., apressure in a range of 10 to 30 bar and all ranges and values therebetween including ranges of 10 to 12 bar, 12 to 14 bar, 14 to 16 bar, 16to 18 bar, 18 to 20 bar, 20 to 22 bar, 22 to 24 bar, 24 to 26 bar, 26 to28 bar, and 28 to 30 bar, a WHSV of 2 to 8 h⁻¹ and all ranges and valuesthere between including ranges of 2 to 3 h⁻¹, 3 to 4 h⁻¹, 4 to 5 h⁻¹, 5to 6 h⁻¹, 6 to 7 h⁻¹, and 7 to 8 h⁻¹, and in the presence of a catalystcomprising Ni/Al₂O₃ to Pd/Al₂O₃.

At block 202, according to embodiments of the invention, stream 102,which comprises hydrogenated C₉₊ compounds is flowed to flash drum 116,wherein stream 102 is separated to produce stream 103 comprisinghydrogenated wash oil and stream 104 comprising hydrogenated C₉₊compounds. In embodiments of the invention, stream 103 comprises 0 to 90wt. % wash oil and all ranges and values there between including rangesof 0 to 10 wt. %, 10 to 20 wt. %, 20 to 30 wt. %, 30 to 40 wt. %, 40 to50 wt. %, 50 to 60 wt. %, 60 to 70 wt. %, 70 to 80 wt. %, and 80 to 90wt. %, and stream 104 comprises 10 to 100 wt. % hydrogenated C₉₊compounds and all ranges and values there between including ranges of 10to 20 wt. %, 20 to 30 wt. %, 30 to 40 wt. %, 40 to 50 wt. %, 50 to 60wt. %, 60 to 70 wt. %, 70 to 80 wt. %, 80 to 90 wt. %, and 90 to 100 wt.%.

In embodiments of the invention, separating pyrolysis gasoline stream100 (at block 200) comprises, as shown at block 201-1, distilling thepyrolysis gas stream in depentanizer column 112 to produce stream 105 asan overhead stream comprising primarily C₄ and C₅ compounds and stream106 as a bottoms stream comprising primarily C₆₊ compounds. In this way,according to embodiments of the invention, a C₄ to C₅ fraction isseparated as an un-hydrogenated stream upstream of any GHU. Thisprovides an advantage where valuable diene components can be separatedfrom this stream. In embodiments of the invention, separating pyrolysisgasoline stream 100 further includes, at block 201-2, flowing stream 106from depentanizer column 112 to deoctanizer column 113 and distillingstream 106 in deoctanizer column 113 to produce stream 107 comprisingprimarily C₆ to C₈ compounds and un-hydrogenated C₉₊ compounds/stream101. More specifically, at deoctanizer column 113, un-hydrogenated BTXis flowed from the top for deoctanizer column 113 and un-hydrogenatedC₉₊ compounds are flowed from the bottom of deoctanizer column 113. Theun-hydrogenated C₉₊ compounds can be used un-hydrogenated or, ifnecessary, can be hydrogenated by passing through GHU reactor 115. Thisis possible because system 10 has the flexibility to be operated in anymode, either hydrogenated, un-hydrogenated, or a combination of both. Inembodiments of the invention, a separation flash drum can be installedbefore GHU reactor 115, where an overhead un-hydrogenated wash oil andbottom un-hydrogenated C₉₊ residue can be produced. The separation ofthe un-hydrogenated C₉₊ compounds/stream 101 can require the operationof deoctanizer column 113 at low temperature, for example, 70 to 100° C.and all ranges and values there between including ranges of 70 to 75°C., 75 to 80° C., 80 to 85° C., 85 to 90 ° C., 90 to 95 ° C., and 95 to100 ° C., on the reboiler and at high vacuum, for example 0.04 to 0.9bara and ranges and values there between including ranges of 0.04 to 0.1bara, 0.1 to 0.2 bara, 0.2 to 0.3 bara, 0.3 to 0.4 bara, 0.4 to 0.5bara, 0.5 to 0.6 bara, 0.6 to 0.7 bara, 0.7 to 0.8 bara, and 0.8 to 0.9bara. Low temperature can be achieved by using the reboiler condensate.And to reduce fouling, a fouling inhibitor can be injected in thedeoctanizer column and/or the depentanizer column. Thus, as shown inFIG. 1, TBC package 120 supplies 4-tert-Butylcatechol (TBC), an organicchemical compound, as a fouling inhibitor to depentanizer column 112 anddeoctanizer column 113.

Process 20 may further include, at block 203, flowing stream 107 fromdeoctanizer column 113 to GHU reactor 114 and hydrogenating stream 107in GHU reactor 114 to produce stream 108 comprising benzene, toluene,and xylene. According to embodiments of the invention, the reactionconditions in GHU reactor 114 include a temperature in a range of 100°C. to 200° C. and all ranges and values there between including rangesof 100 to 110° C., 110 to 120° C., 120 to 130° C., 130to 140° C., 140 to150° C., 150 to 160° C., 160 to 170° C., 170 to 180° C., 180 to 190° C.,and 190 to 200° C., a pressure in a range of 10 to 30 bar and all rangesand values there between including ranges of 10 to 12 bar, 12 to 14 bar,14 to 16 bar, 16 to 18 bar, 18 to 20 bar, 20 to 22 bar, 22 to 24 bar, 24to 26 bar, 26 to 28 bar, and 28 to 30 bar, a WHSV of 2 to 8 h⁻¹ and allranges and values there between including ranges of 2 to 3 h⁻¹, 3 to 4h⁻¹, 4 to 5 h⁻¹, 5 to 6 h⁻¹, 6 to 7 h⁻¹, and 7 to 8 h⁻¹, and in thepresence of a catalyst comprising Ni/Al₂O₃ to Pd/Al₂O₃.

According to embodiments of the invention, process 20, includes, atblock 204, flowing stream 105 from depentanizer column 112 to stabilizer117 and processing stream 105 in stabilizer 117 to produce stream 109comprising fuel gas and stream 110 comprising primarily C₄ and C₅compounds. Block 205 involves flowing stream 110 from stabilizer 117 toGHU reactor 118 and hydrogenating stream 110, in GHU reactor 118, toproduce stream 111 comprising primarily hydrogenated C₄ and C₅compounds, in embodiments of the invention. According to embodiments ofthe invention, the reaction conditions in GHU reactor 118 includes atemperature in a range of 40 to 140° C. and all ranges and values therebetween including ranges of 40 to 50° C., 50 to 60° C., 60 to 70° C., 70to 80° C., 80 to 90° C., 90 to 100° C., 100 to 110° C., 110 to 120° C.,120 to 130° C., and 130 to 240° C., a pressure in a range of 20 to 40bar and all ranges and values there between including ranges of 20 to 22bar, 22 to 24 bar, 24 to 26 bar, 26 to 28 bar, 28 to 30 bar, 30 to 32bar, 32 to 34 bar, 34 to 36 bar, 36 to 38 bar, and 38 to 40 bar, a WHSVof 10 to 16 h⁻¹ and all ranges and values there between including rangesof 10 to 11 h⁻¹, 11 to 12 h⁻¹, 12 to 13 h⁻¹, 13 to 14 h⁻¹, 14 to 15 h⁻¹,and 15 to 16 h⁻¹, and in the presence of a catalyst comprising Ni/Al₂O₃to Pd/Al₂O₃.

Process 20 may further include, at block 206, flowing stream 111 fromGHU reactor 118 to cracker 119 and subjecting stream 111 to crackingconditions in cracker 119 to form C₂ to C₄ light olefin, LPG, and H₂ incracker effluent stream 122.

FIG. 3 shows system 30 for processing pyrolysis gasoline to produce astream comprising primarily un-hydrogenated C₉₊ compounds, according toembodiments of the invention. FIG. 4 shows process 40 for processingpyrolysis gasoline to produce a stream comprising primarilyun-hydrogenated C₉₊ compounds, according to embodiments of theinvention. System 30 may be used to implement process 40. System 30,according to embodiments of the invention, includes the elements 100 to122 of system 10 as well as further elements 300 to 309. Likewise,process 40, in embodiments of the invention, includes operating elements100 to 122 to carry out steps of blocks 200 to 206 as described inprocess 20.

Process 40 as implemented by system 30, like process 20 implemented bysystem 10, includes blocks 200 to 206, in embodiments of the invention,except that GHU reactor 118 is not required as reactor 304 canhydrogenate stream 110 and GHU reactor 114 is similarly not required.Process 40 further includes, at block 400, routing stream 103, stream107, and stream 110 to feed drum 300 where they are combined to formcombined stream 301. Hydrogenation of the combined stream 301 may becarried out by injecting hydrogen stream 302, as shown at block 401, toform hydrogenated combined stream 303. Block 402 involves, inembodiments of the invention, flowing hydrogenated combined stream 303to reactor 304, where hydrogenated combined stream 303 is subjected toreaction conditions sufficient to saturate diolefins and partiallysaturate the olefins. According to embodiments of the invention, stream305 is used to heat hydrogenated combined stream 303 in heat exchanger306. At block 403, stream 305 is separated in separator 307 to formvapor stream 308 comprising water and H₂ and stream 309. At block 404,stream 309 is split into two portions, stream 309-1 and stream 309-2. Inembodiments of the invention, at block 405, stream 309-2 is recycled toreactor 304. At block 406, stream 309-1 is separated to form a BTXstream, a stream comprising primarily hydrogenated wash oil, a fuel gasstream and a stream comprising primarily C₅ compounds.

Although embodiments of the present invention have been described withreference to blocks of FIG. 2 and FIG. 4, it should be appreciated thatoperation of the present invention is not limited to the particularblocks and/or the particular order of the blocks illustrated in FIG. 2and FIG. 4. Accordingly, embodiments of the invention may providefunctionality as described herein using various blocks in a sequencedifferent than that of FIG. 2 and FIG. 4. It should be noted that, inFIG. 1 and FIG. 3, a stream shown from a first element or apparatus to asecond element or apparatus is a disclosure that the first element orapparatus is in fluid communication with the second element or apparatusin a manner such that the flow of the stream shown, or described in thespecification, can take place.

The systems and processes described herein can also include variousequipment that is not shown and is known to one of skill in the art ofchemical processing. For example, some controllers, piping, computers,valves, pumps, heaters, thermocouples, pressure indicators, mixers, heatexchangers, and the like may not be shown.

In the context of the present invention, at least the following20embodiments are shown. Embodiment 1 is a method of processingpyrolysis gasoline. The method includes separating a pyrolysis gasolinestream to produce a first stream containing primarily un-hydrogenatedC₉₊ compounds. Embodiment 2 is the method of embodiment 1 wherein thefirst stream contains 98 to 100 wt. % C₉₊ compounds. Embodiment 3 is themethod of embodiment 1 further including hydrogenating a portion of thefirst stream to produce a second stream containing hydrogenated C₉₊hydrogenated compounds. Embodiment 4 is the method of embodiment 3,wherein the hydrogenating of the first portion of the first stream iscarried out under reaction conditions including a temperature in a rangeof 100° C. to 200° C., a pressure in a range of 10 bar to 30 bar, a WHSVof 2 ⁻¹ to 8 h⁻¹, and in the presence of a catalyst containing Ni/Al₂O₃to Pd/A₂O₃. Embodiment 5 is the method of either of embodiments 3 or 4further including separating the second stream to produce a third streamcontaining hydrogenated wash oil and a fourth stream containinghydrogenated C₉₊ residue. Embodiment 6 is the method of embodimentwherein third stream contains 0 to 90 wt. % wash oil and the fourthstream contains 10 to 100 wt. % hydrogenated C₉₊ compounds. Embodiment 7is the method of either of embodiments 5 or 6, further includingsubjecting the third stream to reaction conditions to hydrogenate thethird stream. Embodiment 8 is the method of embodiment 1, wherein theseparating of the pyrolysis gasoline stream includes distilling thepyrolysis gas stream in a depentanizer column to produce a fifth streamcontaining primarily C₄₊ compounds and a sixth stream containingprimarily C₆₊ compounds. Embodiment 9 is the method of embodiment 8wherein the separating of the pyrolysis gasoline stream further includesdistilling the sixth stream in a deoctanizer column to produce a seventhstream containing primarily C₆ to C₈ compounds and the first stream.Embodiment 10 is the method of embodiment 9 including hydrogenating theseventh stream to produce an eighth stream containing benzene, toluene,and xylene. Embodiment 11 is the method of embodiment 10, wherein thehydrogenating of the seventh stream is carried out under reactionconditions including a temperature in a range of 100° C. to 200° C., apressure in a range of 10 bar to 30 bar, a WHSV of 2 h⁻¹ to 8 h⁻¹, andin presence of a catalyst containing Ni/Al₂O₃ to Pd/Al₂O₃. Embodiment 12is the method of embodiment 8 further including processing the fifthstream in a stabilizer to produce a ninth stream including fuel gas anda tenth stream containing primarily C₄ and C₅ compounds. Embodiment 13is the method of embodiment 12 further including hydrogenating the tenthstream to produce an eleventh stream containing primarily C₄ and C₅compounds. Embodiment 14 is the method of embodiment 13, wherein thehydrogenating of the tenth stream is carried out under reactionconditions including a temperature in a range of 40° C. to 140° C., apressure in a range of 20 bar to 40 bar, a WHSV of 10 h⁻¹ to 16 h⁻¹, andin presence of a catalyst containing Ni/Al₂O₃ to Pd/Al₂O₃. Embodiment 15is the method of either of embodiments 13 or 14 further includingsubjecting the eleventh stream to cracking conditions to form C₂ to C₄light olefins, LPG, and H₂.

Embodiment 16 is method of processing pyrolysis gasoline. The methodincludes concurrently producing (1) a first stream containing primarilyun-hydrogenated C₉₊ compounds and (2) a second stream containinghydrogenated C₉₊ hydrogenated compounds, wherein the producing includesseparating a pyrolysis gasoline stream to produce the first streamcontaining primarily un-hydrogenated C₉₊ compounds and hydrogenating aportion of the first stream to produce the second stream containinghydrogenated C₉₊ hydrogenated compounds. Embodiment 17 is the method ofembodiment 16 further including producing a stream containing primarilyun-hydrogenated C₄₊ compounds.

Embodiment 18 is a method of processing pyrolysis gasoline. The methodincludes separating a pyrolysis gasoline stream to produce a firststream containing primarily un-hydrogenated C₉₊ compounds andhydrogenating a portion of the first stream to produce a second streamcontaining hydrogenated C₉₊ compounds. The method further includesseparating the second stream to produce a third stream containinghydrogenated wash oil and a fourth stream containing hydrogenated C₉₊residue The separating of the pyrolysis gasoline stream includesdistilling the pyrolysis gas stream in a depentanizer column to producea fifth stream containing primarily C₄₊ compounds and a sixth streamcontaining primarily C₆₊ compounds. The method also includes distillingthe sixth stream in a deoctanizer column to produce a seventh streamcontaining primarily C₆ to C₈ compounds and the first stream. Inaddition, the method includes processing the fifth stream in astabilizer to produce a ninth stream containing fuel gas and a tenthstream containing primarily C₄ and C₅ compounds. The method furtherincludes combining the third stream, the seventh stream, and the tenthstream to form a combined stream and flowing the combined stream to areactor. Embodiment 19 is the method of embodiment 18, further includingsubjecting the combined stream to reaction conditions sufficient to forma reactor effluent. Embodiment 20 is the method of embodiment 19 furtherincluding processing the reactor effluent to produce a BTX stream, astream containing primarily hydrogenated wash oil, a fuel gas stream anda stream containing primarily C₅ compounds.

EXAMPLES

The present invention will be described in greater detail by way ofspecific examples. The following examples are offered for illustrativepurposes only, and are not intended to limit the invention in anymanner. Those of skill in the art will readily recognize a variety ofnoncritical parameters which can be changed or modified to yieldessentially the same results.

Example 1 Producing Un-hydrogenated C₉₊ Compounds from PyrolysisGasoline

A first cut model was built in Aspen-Plus V10 Software. Simulations wereperformed according to an embodiment of the current disclosure as shownin FIG. 5. Separated streams containing C₄-C₅ compounds, un-hydrogenatedC₆ to C₈ compounds, un-hydrogenated wash oil, un-hydrogenated C₉₊residues were obtained from a pyrolysis gasoline stream. The pyrolysisgasoline stream contained C₄ compounds, C₅ compounds, benzene, toluene,xylene, styrene, indene, indane, dicyclopentadiene (DCPD),methyldicyclopentadiene (MDCPD), and others (e.g. other C₆-C₈ paraffinicand olefinic components, and C₉₊ paraffinic, olefinic, napthenic andaromatic components). The pyrolysis gasoline stream was distilled in adepentanizer column to obtain a stream containing the C₄ and C₅compounds from the top of the column, and a C₆₊ stream containingun-hydrogenated C₆₊ compounds from the bottom of the column. The C₆₊stream contained benzene, toluene, xylene, styrene, indene, indane,DCPD, MDCPD and the other. The C₆₊ stream was distilled in a deoctanizercolumn to obtain a C₆₋₈ stream containing un-hydrogenated C₆ to C₈compounds from the top of the column, and a C₉₊ stream containingun-hydrogenated C₉₊ compounds from the bottom of the column. The C₆₋₈stream contained benzene, toluene, xylene and a portion of other (e.g.C₆-C₈ paraffinic and olefinic components). The C₉₊ stream containedstyrene, indene, indane, DCPD, MDCPD and a portion of the other (e.g.C₉₊ paraffinic, olefinic, napthenic and aromatic components). The C₉₊stream was separated in a separation flash drum to obtain a streamcontaining un-hydrogenated wash oil from the top and a stream containingun-hydrogenated C₉₊ residues from the bottom. The compositions, flowrate of the streams are provided in Tables 1-7. A TBC package,containing 4-tert-Butylcatechol (TBC) as fouling inhibitor, was suppliedto the depentanizer column, deoctanizer column and the flash drum toreduce fouling.

TABLE 1 Pyrolysis gasoline stream Compounds Ton/hour C₄ 0.59 C₅ 11.16Benzene 14.07 Toluene 2.94 Xylene 0.31 Styrene 1.39 Indene 0.58 Indane0.22 DCPD 1.95 MDCPD 0.3 Others 6.97 Total 40.49

TABLE 2 C₄-C₅ stream Compounds Ton/hour C₄ 0.59 C₅ 11.16 Total 11.75

TABLE 3 C₆₊ stream Compounds Ton/hour Benzene 14.07 Toluene 2.94 Xylene0.31 Styrene 1.39 Indene 0.58 Indane 0.22 DCPD 1.95 MDCPD 0.3 Others6.97 Total 28.74

TABLE 4 C₆₋₈ stream Compounds Ton/hour Benzene 14.00 Toluene 2.78 Xylene0.2 Others 3.72 Total 20.7

TABLE 5 C₉₊ stream Compounds Ton/hour Styrene 0.71 Indene 0.58 Indane0.22 DCPD 1.86 MDCPD 0.3 Others 4.59 Total 8.04

TABLE 6 Wash oil Compounds Ton/hour Styrene 0.65 Indene 0.48 Indane 0.18DCPD 1.55 MDCPD 0.18 Others 3.32 Total 6.35

TABLE 7 C₉₊ residue stream Compounds Ton/hour Styrene 0.06 Indene 0.1Indane 0.04 DCPD 0.31 MDCPD 0.12 Others 1.05 Total 1.69

Although embodiments of the present application and their advantageshave been described in detail, it should be understood that variouschanges, substitutions and alterations can be made herein withoutdeparting from the spirit and scope of the embodiments as defined by theappended claims. Moreover, the scope of the present application is notintended to be limited to the particular embodiments of the process,machine, manufacture, composition of matter, means, methods and stepsdescribed in the specification. As one of ordinary skill in the art willreadily appreciate from the above disclosure, processes, machines,manufacture, compositions of matter, means, methods, or steps, presentlyexisting or later to be developed that perform substantially the samefunction or achieve substantially the same result as the correspondingembodiments described herein may be utilized. Accordingly, the appendedclaims are intended to include within their scope such processes,machines, manufacture, compositions of matter, means, methods, or steps.

1. A method of processing pyrolysis gasoline, the method comprising:separating a pyrolysis gasoline stream to produce a first streamcomprising primarily un-hydrogenated C₉₊ compounds.
 2. The method ofclaim 1 wherein the first stream comprises 98 to 100 wt. % C₉₊compounds.
 3. The method of claim 1 further comprising: hydrogenating aportion of the first stream to produce a second stream comprisinghydrogenated C₉₊ hydrogenated compounds.
 4. The method of claim 3,wherein the hydrogenating of the first portion of the first stream iscarried out under reaction conditions comprising a temperature in arange of 100° C. to 200° C., a pressure in a range of 10 bar to 30 bar,a WHSV of 2 h⁻¹ to 8 h⁻¹, and in the presence of a catalyst comprisingNi/Al₂O₃ to Pd/Al₂O₃.
 5. The method of claim 3 further comprising:separating the second stream to produce a third stream comprisinghydrogenated wash oil and a fourth stream comprising hydrogenated C₉₊residue.
 6. The method of claim 5 wherein third stream comprises 0 to 90wt. % wash oil and the fourth stream comprises 10 to 100 wt. %hydrogenated C₉₊ compounds.
 7. The method of claim 5, furthercomprising: subjecting the third stream to reaction conditions tohydrogenate the third stream.
 8. The method of claim 1, wherein theseparating of the pyrolysis gasoline stream comprises: distilling thepyrolysis gas stream in a depentanizer column to produce a fifth streamcomprising primarily C₄₊ compounds and a sixth stream comprisingprimarily C₆₊ compounds.
 9. The method of claim 8 wherein the separatingof the pyrolysis gasoline stream further comprises: distilling the sixthstream in a deoctanizer column to produce a seventh stream comprisingprimarily C₆ to C₈ compounds and the first stream.
 10. The method ofclaim 9 comprising: hydrogenating the seventh stream to produce aneighth stream comprising benzene, toluene, and xylene.
 11. The method ofclaim 10, wherein the hydrogenating of the seventh stream is carried outunder reaction conditions comprising a temperature in a range of 100° C.to 200° C., a pressure in a range of 10 bar to 30 bar, a WHSV of 2 h⁻¹to 8 h⁻¹, and in presence of a catalyst comprising Ni/Al₂O₃ to Pd/Al₂O₃.12. The method of claim 8 further comprising: processing the fifthstream in a stabilizer to produce a ninth stream comprising fuel gas anda tenth stream comprising primarily C₄ and C₅ compounds.
 13. The methodof claim 12 further comprising: hydrogenating the tenth stream toproduce an eleventh stream comprising primarily C₄ and C₅ compounds. 14.The method of claim 13, wherein the hydrogenating of the tenth stream iscarried out under reaction conditions comprising a temperature in arange of 40° C. to 140° C., a pressure in a range of 20 bar to 40 bar, aWHSV of 10 h⁻¹ to 16 h⁻¹, and in presence of a catalyst comprisingNi/Al₂O₃ to Pd/Al₂O₃.
 15. The method of claim 13 further comprisingsubjecting the eleventh stream to cracking conditions to form C₂ to C₄light olefins, LPG, and H₂.
 16. A method of processing pyrolysisgasoline, the method comprising: concurrently producing (1) a firststream comprising primarily un-hydrogenated C₉₊ compounds and (2) asecond stream comprising hydrogenated C₉₊ hydrogenated compounds,wherein the producing comprises separating a pyrolysis gasoline streamto produce the first stream comprising primarily un-hydrogenated C₉₊compounds and hydrogenating a portion of the first stream to produce thesecond stream comprising hydrogenated C₉₊ hydrogenated compounds. 17.The method of claim 16 further comprising: producing a stream comprisingprimarily un-hydrogenated C₄₊ compounds.
 18. A method of processingpyrolysis gasoline, the method comprising: separating a pyrolysisgasoline stream to produce a first stream comprising primarilyun-hydrogenated C₉₊ compounds; hydrogenating a portion of the firststream to produce a second stream comprising hydrogenated C₉₊ compounds;separating the second stream to produce a third stream comprisinghydrogenated wash oil and a fourth stream comprising hydrogenated C₉₊residue, wherein the separating of the pyrolysis gasoline streamcomprises: distilling the pyrolysis gas stream in a depentanizer columnto produce a fifth stream comprising primarily C₄₊ compounds and a sixthstream comprising primarily C₆₊ compounds; distilling the sixth streamin a deoctanizer column to produce a seventh stream comprising primarilyC₆ to C₈ compounds and the first stream; processing the fifth stream ina stabilizer to produce a ninth stream comprising fuel gas and a tenthstream comprising primarily C₄ and C₅ compounds; and combining the thirdstream, the seventh stream, and the tenth stream to form a combinedstream and flowing the combined stream to a reactor.
 19. The method ofclaim 18, further comprising: subjecting the combined stream to reactionconditions sufficient to form a reactor effluent.
 20. The method ofclaim 19 further comprising: processing the reactor effluent to producea BTX stream, a stream comprising primarily hydrogenated wash oil, afuel gas stream and a stream comprising primarily C₅ compounds.